Method and apparatus for cooling ingot-molds



R. G. COATES.

METHOD AND APPARATUS FOR COOLING INGOT MOLDS.

APPLICATION FILED OCT. 25. 1919.

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3 vwcmko'a f WM Q ttommmg R. G. COATES.

METHOD AND APPARATUS FOR COOLING INGOT MOLDS.

APPLICATION FILED OCT. 25, I919.

L@%5fi49@ atent d July A, 192 0.,

4 SHEETS-SHEET 2.

R. G. COATES.

METHOD AND APPARATUS FOR COOLING INGOT MOLDS.

APPLICATION FILED OCT. 25. 1919.

m Pwmmed July fi M2 0.

4 SHEETS-SHEET 3.

R. G. COATES.

METHOD AND APPARATUS FOR COOLING INGOT MOLDS.

APPLICATION FILED OCT-25.1919.

HmHIlmhj till fllfit ltthtetttlh Application tiled tlctober 5th alt whom it may concern:

Be it known that l, RAY G'. tloa'rns, a citizen of the llnited Edtates, and a resident of the city of Pasadena, in the county of lies Angeles, @tate of California, have 1nvented new and useful llmprovements in Methods and Apparatus tor tloohng lngot- Molds, of which the tollowlng 1s a specification.

This invention relates broadly to metallurgy and more particularly to a method and apparatus for treatment of castings.

"()ne of the principal ob ects ot the pres ent invention is the method of slowly cool ing hot castings which comprises subjecting the casting during a relatively long period of time to a circulating cooling fluid which gradually increases in temperature as it travels over the molds.

Another and primary object of the present invention is the provision of an apparatus for carrying out the method specified in the foregoing paragraph.

A further object of the present invention is the method of treating hot castings which comprises arranging the castings in groups, then successively subjecting the groups of castings to cooling fluids of gradually increasing temperature in such manner that the cooler groups of castings receive the coolest tluids, and the hottest group of castings receives the hottest fluid.

A still further object of the present invention is the provision of the method of treating castings which comprises arranging the castings in series in such manner that the hottest castings are added to one end of the series and the cool castings are taken from the other end of the series, and subjecting the castings to cooling fluid which travels from the coolest castings toward the hottest castings.

Another and further object of the present invention is the method of treating ingot mold castings, and the like. which method comprises arranging the ingot molds in series and within the path ot a traveling cooling fluid, adding hot ingot molds to one end of the series and removing cooled molds from the other end of the series while iausing the cooling fluid to travel over the series from the coolest molds to the hottest molds.

specification ot' Letters .lPateht.

Patented July t3, tlhfitlt iota. serial no. steam.

Astill further object of the present inventlon is the treatment of large castings and wherein the castings are positioned in a line and according to a heat gradient; then subjecting the castings to a traveling coolmg tluid which is maintained at a graduated temperature in such manner as to pro 'vide a relatively small temperature difterential between the fluid and the castings throughout the portion of the line in contact with the cooling fluid.

Another and still further object of the present invention is the process of treating castings without use of additional heat which comprises removing the hot castings from the molds, arranging the castings in a chamber having open ends, and circulating a cooling tluid through the chamber in such manner that the fluid passes from the coolest to the hottest castings. Y

Another and important object of the present invention is the process of cooling ingot molds, or other large castings, which comprises arranging the molds in a line of predetermined length within a covered chamber, adding hot castings to one end of the line and removing cooled castings from the other end of the line, and then providing a draft of air over the castings in such manner that the direction of the movement of the air is from the cooled castings toward the hot castings, and maintaining the walls of the chamber at a temperature slightly below that of the adjacent molds.

Another object of the present invention is the process of treating ingot molds, and

other large castings, which comprises arranging the molds in series in such manner as to comprise a line of molds, moving the line progressively through a covered channel, removing castings from one end of the line at substantially the same rate as castings are added to the other end of the line, and causing a cooling fluid such as air to move in the opposite direction to the progression of the line of molds.

Another and also important object of the present invention is a device for treating ingot molds, said device comprising a covered channel formed of slow heat-conducting materials. with the channel constructed to receive ingot molds and the like at a charging station, and to discharge cooled ingot molds and the like at a discharging station, and with the said channel provided with passagemiys and constructions ad apted to provide a movement of cooling air which moves from the coolest molds through the channel and is discharged from adjacent the hottest molds.

A still more specific object of the present invention is an apparatus for cooling ingot molds and the like which apparatus comprises, in its specific preferred form, a circularly arranged covered channel provided with an open receiving station and an open discharging station, a movable floor-way within said channel, a partition separating the discharging station and the receiving station, and with the channel having passageways for causing air to enter ad acent the discharging station, and to circulate through the channel and be discharged adjacent the charging station.

Referring now to the drawings, Figure 1 is a plan view of one form of device for carrying out the present invent on.

Fig. 2 is a cross-section on line Ai\ of Fig. 1.

Fig. 3 is an elevational view of the devlce shown in Fig. 1. I

Fig. 4 is a perspective view of the device shown in Fig. l.

Fig. 5 is a sectional plan view of a different form of device for carrying out the present invention.

Heretofore in the art of cooling large castings, several procedures have been at tempted, and I will refer to procedures common in the art of manufacturing ingot molds as illustrative of the prevailing methods. Ingot molds are manufactured in substantially standard sizes in large quantities, and therefore a foundry making ingot molds will produce large quantities of castings of similar sizes and shapes and which are manufactured under similar conditions. It is not desirable to permit a large casting for ingot molds to cool too rapidly because rapid cooling may cause undesirable crystallization to occur, which may tend to weaken the casting. To obviate this difficulty it is the common practice in the treatment of ingot molds to leave the castings in the sand with their flasks and core bars in position until the casting has cooled. This seriously ties up equipment necessary for the manufacture of ingot molds and consequently interferes with efiicient operation of the foundry. Another common practice is to remove the flasks and core bars, breaking the adhering sand as little as possible. This method releases equipment, but leaves the casting with far too little covering and permits too rapid cooling, and at the same time seriously interferes with the working conditions on the foundry floor, and is a very unsatisfactory way of treating ingot mold castings. A

third example of common practice. is where the flask and core bar are. removed and the castings with the adhering sand are piled up into a hot pile and are then allowed to stand for a predetermined time. to permit the castings to cool slowly. This latter practice produces unevenly treated molds because the molds in the pile are subjected to extreme conditions due to the occurrences within the hot pile itself. These hot piles may represent from one-half to one thousand tons of castings which are piled up during several hours of work, and are then permitted to stand for twenty to twenty-four hours, when the pile is taken down during several more hours of labor. The molds on the outside of the pile are the. last put on and the first taken off. The heat of the pile causes strong convectional air currents which draw relatively cool air to aid the pile. This cool air strikes the outside molds and therefore subjects them to rapid and severe cooling conditions. These outside molds therefore cool much more quickly than the molds in the middle of the pile, although the latter were the first to go into the pile. The interior molds therefore. receive more heat from adjacent molds, and no cool air strikes these interior molds during the cooling period. It therefore is evident that the interior molds are treated to the opposite extreme from the molds of the exterior of the pile. There is therefore a large difference in the cooling rates in the different parts of the pile and consequently a large difference in the condition of the molds when received from the pile. This condition is unsatisfactory irrespective of the labor required to make and unmake the piles. and the delay occasioned by this manipulation causes the castings to move through the finishing processes in a very uneven manner, so the work is periodically rushed with intervening periods of idleness. It is obvious that very few molds from the hot pile are subjected to average conditions, therefore few molds come out in the best. condition for subsequent treatment and use.

The present invention overcomes the chiliculties of the known art by providing gradual cooling without subjecting the molds to severe plunges of cooling fluid and provides an even progression during the cooling treatment so that the labor and shop conditions are substantially uniform where.' by a substantially uniform supply of molds is furnished for finishing purposes. In carrying out the present invention for cooling ingot molds, the core bars are stripped from the castings and the latte are shaken out of the flasks as soon as the castings are safe to be handled. This permits immediate release of the equipment so that it is again ready for immediate use. The castings are then set in a line, preferably although not lbt) ' necessarily, on moi floor in a cot cred, passage or channel. lie line may he one or several castings wire, hi preferably the line is so arranged that additional hot or at ings may continually be added to one end thereof. llf the merit floor." is provided, hot castings are set a no end of the line andthe floor moves to carry these castings forward and to provide clear floor space for receiving other hot castings. When the line has reached a prerileterniined length, air

is admitted into the channel in a direction contrary to the progression of the line in such manner that the air current passes from those castings first placed in the line over those which have been later successively positioned. Tn view of this arrange ment it is evident that the air striking the hot castings is air which has been heated by the next castings toward the air supply, and that the last castings at the hot end of the line receive the air which has been heated by all of the other castings over which the air has passed. This condition produes a gradual drop in temperature of the castings, and the cooling is very evenly divided over the entire cooling arrangement. fiince the air is gradually heated as it rogresses, the heat gradient of the air is slimlar to the heat gradient of the series of molds; therefore the temperature differential between the air and the molds is relatively low and substantially uniform. Furthermore, every casting in the line is subjected to the same conditions as every other casting so that, with the conditions arranged as nearly ideal as may be obtained, each casting is therefore subjected to a substantially ideal cooling treatment. After the line has beenin operation for a predeter mined length of time, the first castings placed in the line are removed and other castings are added to the opposite end of the line. The line thus becomes permanent and while hot castings are being added to one end, the cool castings may be removed from the other.

Furthermore, where a moving platform is utilized in a stationary pasageway, the sides of the channel in which the castings are placed soon become heated to nearly the temperature of the adjacent castings so that the pasageway maintains zones of gradually increasing temperature from the discharge end of the passageway to the charging end thereof. The castings go in hot and come out cool while the air comes in cool and leaves the channel at a high temperature. The line of molds therefore resembles a sort of coarse checker work which is hot to begin with and is used but once. In a certain sense the line of molds is a gradually moving stream which is hot at the source and gradually loses temperature as it progresses toward the outlet.

s a soaking period and the other of which is a cooling period. lfn practice as outlined in accordance with the present invention,it will be noted that no heat is applied to the castings other than the heat which is 1n the casting when it enters the treatment chamber. Where the progressive cooling begins, each moldis cooler than the one put 1n later, and there is no rise in temperature in the castings except such as may result from internal changes in the castings, and as soon as any such changes occur the piold immediately starts to lose temperaare.

Where the operations are carried out on a moving floor, the charging point and discharging point for the castings are both fixed, while the floor of the channel moves forwardly from the charging point to the discharging station. Where the floor of the channel is stationary, merely the charging and discharging points are progressive. lfn either case the apparatus should preferably be arranged in such manner that the chan nel is an inclosed circuit, so that with the stationary door the points return to the original starting positions.

For the moving floor type it is preferable that the horizontal plan of the channel shall be circular, although it is not necessarily so as with the non-moving floor, which may be almost any form provided it is suitably divided into sections for charging, discharg; ing, etc. The general plan of the channel should have one cross-section dimension greater than the other and this larger dimension' should provide for the ample supply of air in its passage over the line of molds. lBy predetermining or regulating proper cross-section of the channel, the progression of the line of molds in the channel, the amount of air passing through the channel, and the point of diversion of air from the channel, the entire sequence of the cooling process may be maintained constant or varied, as the conditions require or as may be desired.

By the foregoing general description of my invention it will be seen that l have provided for treating molds collectively and at the same time have insured that each individual mold will receive exactly the same treatment as every other individual mold,

lllltl and the treatment is so devised as to facilitate working conditions in the foundry.

Referring now to the drawings, 1 have illustrated certain forms of the apparatus for carrying out my invention.

onsidering now more especially Figs. 1 to 4, which illustrate one form of construction for carrying out the present invention, a circular channel 1 is shown as provided with a permanent covering 2 which covers the larger portion of the channel. The open portion of the channel is divided by a partition wall 4 into two open vestibules, one comprising a loading vestibule 5 and the other an unloading vestibule 6. The front side wall of the channel adjacent these vestibules is cut away in such manner as to facilitate the handling of the castings. The back wall extends upwardly and terminates adjacent the cover. The front and back walls carry curved tracks 7 and 8 upon i which a movable cover 9 is adapted to travel so that either the discharging vestibule or the loading vestibule may be covered when desired. Ordinarily but a single cover member is provided; however it may be desirable to supply a pair of covers capable of closing both vcstibules.

A sliding gate 10 may be provided adjacent the loading vestibule to prevent the entrance of cold air to the channel during the loading operation. Adjacent the loading platform and extended some distance therefrom there is provided a flue 11 for conducting the hot gases and air away from the channel. This flue preferably extends concentric with the channel for a portion of its periphery, and at suitable intervals passageways 12 are provided between the channel and the flue. These passageways a re controlled by suitable gates or doors 14:,

so that the point at which the air from the channel begins to flow into the flue may be under the control of the operator in such manner as to provide an area in which no cooling fluid is passing over the hot molds, and such a part of the channel may comprise a soaking pit. The channel may be provided with a continuous moving floor 15 which is provided with rails 16 that roll upon rollers 17 and 18 which are mounted to roll upon stationary tracks 19. rollers are connected by a suitable roller cage 20, and the rollers 18 of one set preferably are flanged while the rollers 17 preferably are not flanged. This construction facilitates maintaining the parts in alinement and at the same time permitting sufficient freedom of movement to obviate binding.

The sides of the channel are provided with troughs 21 and 22, and the movable floor is provided with depending plates 24 and 25 which extend into the troughs. The

These" troughs may be filled with any suitable material, such as will withstand the heat, in order to prevent the heat from within the channel from escaping into the lower part thereof. Preferably the central portion of the channel between the tracks is provided with a depression 26 which may comprise a manway for repair and inspection of the moving parts.

The floor may be moved in various ways; preferably, however, electric motors 27 are mounted at suitable intervals on the roller cage and are geared in a suitable manner to the shafts of the rollers 17 and 18. The motors may be supplied with electricity from a third rail 28. The electric motors may be controlled by a suitable controlling mechanism and the moving floor may there.- fore be moved when required. The ingot molds or other castings 25) are placed on the moving floor in the space comprising the loading vestibule. and after this vestibulc has been filled, preferably the movable covcr ii is positioned over the hot molds thereby closing the loading vestibule. After the vestibule has been closed, the sliding gate 10 is opened. The discharging vcsti bule is now free for unloading and the ingot molds standing on the movable floor or in the sliding vestibule are removed. The moving floor is then turned a sullicient distance to carry the hot molds from the loading vestibule into the soaking pit" and to trans fer the empty space from the discharge vestibule to the loading vestibule, so that the loading vestibule is now free to be loaded again and the discharge vestibule is filled with molds for unloading. In view of the fact that the molds :arry considerable sand which accumulates on the moving floor. it is necessary to provide for scraping and for removing the sand from the part of the moving floor which passes under the partition 4. Therefore a sand conveyer 30 is mounted adjacent the partition 4 and scrapes a part of the sand from the platform into the sand chute 31. It is prefc able that the upper portion of the moving platform be covered with sand in order to provide a suitable material for withstanding rough usage and at the same time providing a good nonconductor of heat. In the construction of this type of cooling nit it will be noted that the air enters the discharging vestibule over the coolest Zone of molds and travels along the channel to an open passageway 12 between the channel and the flue 11. so that the movement of air is opposite to the movement of the molds. while the temperature of the air corresponds to the temperature of the molds, that is, the coolest air is over the coolest molds, and the hottest air is over the hottest molds which emerge from the soaking pit portion of the channel. The temiii til

ill

net-area perature of the air, however, is less than that of the molds so consequently heat is continually transferred from the molds to the moving air. The air may be mechanically circulated or it may be drawn through a chimney or flue to some point where heated air is desired in the operation of the plant. The removable covers 9 or some similar means may be manipulated to control the amount of air entering the channel. However, the movement of the air is substantiallycontrolled' by means of the doors or gates in the passageways 12 between the flue and the channel.

Fig. 5 illustrates one form of stationary construction in which the present invention may be carried out. The form as illustrated comprises a covered channel 32 having an inside wall 34 and an outside wall 35. The outside wall is provided with a plurality of passageways 36 closed by suitable doors 37. The inside wall is also provided with a plurality of passageways 38 which are controlled by doors or gates 39. Suitable movable partitions 40 are provided in such manner that the channel may be partitioned at any point between the passageways 36 and 38. A suitable chimney or flue 41 leads to the inclosure formed by the inside walls 34:.

In the operation of this device the discharging and charging stations move around the channel and the operation may be carried on in the following manner. As shown in 1F ig. 5, the passageway 36, indicated as A, is open, the partition B is closed, wh le the passageway C is open. Under these c1rcumstances the portion of the channel adjacent the passageway becomes a charging station, and the air enters through the passageway A and moves in the direction of the arrow along the channel to the open passageway C from which the air travels into the flue or chimney 41. As soon as the charging station is filled, the movable partition B is opened, the door C is closed, and the door C is opened, and the partition door B is closed, while the outside door A is opened to permit the cool molds to be removed and hot molds to take their places. The operation of this device is similar to that previously described in that the air enters over the cooler molds and passes along over the molds which are arranged in gradually increasing temperatures so that the air passes away from the point ad acent the hottest zone of the molds. The molds are arranged in series with the hot molds at one end of the series and the cool molds at the other end, with molds being added adjacent the hot end of the series and removed from the cool end. The primary distinction between the moving floor type and the stationary floor type is that the point of charging and discharging the molds is stationary in the first type and travels around the channel in the second type.

From the foregoing description it will be seen that the treatment of the castings is gradient of the air may be slightly greater than that of the castings so that the differential between the castings and the air gradually decreases in such manner that the greatest temperature differential is between the hottest castings and the hottest air, and the cool castings are substantially at the same temperature as atmosphere or only slightly above that point.

The present invention possesses many other and advantageous features, and it is to be understood that the drawings and specification disclose only the preferred form of the invention, and it is to be understood that I do not limit myself to such form because my invention may be practised and embodied in a multiplicity of forms and procedures, each being a species of my invention, it being understood by the claims succeeding the description of my invention that I desire to cover the invention in whatsoever form it may be embodied or practised.

I claim:

1. The method of treating large castings which comprises removing the castings from their respective molds and arranging the castings in open groups immediately after the castings have hardened and before the hardened castings have begun to cool to any substantial degree; then subjecting the groups of castings to a heated cooling fluid of a less temperature than the castings; then gradually decreasing the temperature of the cooling fluid to maintain a suitable temperature diderential between the cooling fluid and the castings to cause the castings to gradually cool.

2. The method of treating large castings which comprises removing the castings from their respective molds and arranging the castings in open groups immediately after the castings have hardened and before the hardened castings have begun to cool to any substantial degree; then subjecting the groups of castings to a traveling heated cooling fluid of a less temperature than the castings; then gradually decreasing the temperature of the cooling fluid that contacts with a particular group of castings to main tain a suitable temperature differential between the cooling fluid and the castings to cause the castings to gradually cool.

3. The method of treating a large casting which comprises removing the casting from its mold and immediately after the casting has hardened and before the hardened casting has begun to cool to any substantial degree; then subjecting the casting to a heated cooling fluid'ot a less temperature than the casting; then gradually decreasing the temperature of the cooling fluid to maintain a suitable temperature differential between the cooling fluid and the casting to cause the casting to gradually cool.

4. The method of. treatingcastings and the like which comprises arranging hot castings in a series; causing a current of air to move over the series; removing cooled castings from the end of the series from which the air current is moving, and adding hot castings to the end of the series toward which the air is moving.

5. The method of treating castings and the like which comprises arranging hot castings in a continuous series; causing a current ox" air to move over the series; removing cooled castings from the portion of the series from which the air current is moving and adding hot castings to the portion of the series toward which the air is moving.

(3. The method of treating castings and the like which comprises arranging hot castings in a series; causing the series to move; causing a current of air to move over the series in a direction opposite to the movement of the series; removing cooled castings from the end of the series from which the air current is moving and adding hot castings to the end of the series toward which the air is moving.

7. The method of treating castings and the like which comprises arranging hot castings in a continuous series; causing the series to move; causing a current of air to move over the series in a direction opposite to the movement of the series; removing cooled castings from the portion of the series from which the air current is moving,

and adding hot castings to the portion of the series toward which the air is moving.

8. The method of treating castings and the like which comprises removing castings from their mold flasks when the castings are sufficiently cool to be moved without injury; then arranging the hot castings in series; then causing the castings in the series to progress by adding equal amounts of castings to one end of the series and removing equal amounts from the other end of the series; then causidg cooling air to travei over the castings in a direction opposite to the progressive movement of the castings, whereby the temperature of the air is raised so that the hottest portion of the traveling air is adjacent the hottest castings in the series.

9. The method of treating castings and the like which comprises rcn'ioving castings from their mold flasks when the castings are sutliciently cool to be moved without injury; then arranging the hot -astings in series within a walled chamber; then causing the castings in the series to progress by adding equal amounts of castings to one end of the series and removing equal amounts from the other end of the series;

maintaining the walls of the chamber at a temperature slightly less than the adjacent castings; then causing cooling air to travel over the castings in a tilltttinfl opposite to the progressive movement of tin castings, whereby the temperature of they air is raised so that the hottest portion of the traveling air is adjacent the hottest cast.- ings in the series.

10. The method of treating castings and the like which comprises removing castings trom their mold flasks when the cas ings are sutliciently cool to be moved witlu out injury; then arranging the hot castings in series within a chamber; thcn causing the 'astings to move through the chamber; adding equal amounts of castings to o.i. end of the series and removing cqnat amounts from the other end ot thc sci-its: then subjecting the castings to cooling aii within the chamber, whereby the. temperature oi" the air is raised so that the hottest portion of the traveling air is adjacent the hottest castings in the series. I

11. The method ot treating large casting such as ingot molds and the like. which method con'ipriscs arranging the castings n a temperature-grinled series with one end t the series comprising cool castings and the other end of the series comprising hot cast ings; passing a current of air over the scrim in such manner that the current moves tron. the cooled castings toward the hot castings; and removing the cooled castings from one end of the series and adding hot castings to the other end of the series.

12. The method of treating large castings. such as ingot molds and the like. which method comprises arranging the castings in a temperature-gradcd series with one cnd ot the series comprising cool castings and the other end of the series comprising hot castings; and passing a current ot air over the series in such manner that the current moves from the cooled castings toward the hot castings.

13. The method of treating large castings, such as ingot molds and the like. which method comprises ar -anging the castings in Illl till

all

till

ectare-a a temperature-graded series within a walled chamber and with one end of the series comprising cool castings and the other end of the series comprising hot castings; and passing a current of air over the series in such manner that the current moves from the cooled castings toward the hot castings.

ll. The method of treating large castings, such as ingot molds and the like, which method comprises arranging the castings in a temperature-graded series within a walled chamber and with one end of the series comprising cool castings and the other end of the series comprising hot castings; maintaining the walls of the chamber at a temperature slightly less than the adjacent castings; and passing a current of air over the series in such manner that the current moves from the cooled castings toward the hot castings.

15. The method of treating large castings, such as ingot molds and the like, which method comprises arranging the castings in a heat-graded series of a predetermined length; causing a current of air to move over the castings from the cool end of the series toward the hot end thereof, and maintaining the heat gradient of the air slightly lower than the heat gradient of the series of castings. whereby a suitable temperature difierential is maintained between the air and the castings; then removing cooled castings from one end of the series and adding hot castings, as taken from the molds, to the other end of the series to maintain the length of the series substantially constant during working conditions.

16. The method of treating large castings, such as ingot molds and the like, which method comprises arranging the castings in a heat-graded series of a predetermined length; subjecting the castings to cooling air; and maintaining the heat gradient of the air slightly lower than the heat gradient of the series of castings whereby a suitable temperature differential is maintained between the air and the castings; then removing cooled castings from one end of the series and adding hot castings, as taken from the molds, to the other end of the series to maintain the length of the series substantially constant during working conditions.

17. The method of treating large castings, such as ingot molds and the like, which method comprises arranging the castings in a heat-graded series of a predetermined length; causing a current of air to move over the castings from the cool end of the series toward the hot end thereof, and maintaining the heat gradient of the air slightly lower than the heat gradient of the series of castings whereby a suitable temperature differential is maintained between the air and the castings.

18. The method of treating large castings, such as ingot molds and'the like, which method comprises arranging the castings in a heat-graded series of a predetermined length; subjecting the castings to cooling air, and maintaining the heat gradient of the air slightly lower than the heat gradient of the series of castings, whereby a suitable temperature differential is maintained between the air and the castings.

19. The method of treating large castings, such as ingot molds and the like, which method comprises arranging the castings in a heat-graded series of a predetermined length; causing a current of air to move over the castings from the cool end of the series toward the hot end thereof, and maintaining the heat gradient of the air slightly lower than the heat gradient of the series of castings whereby a suitable temperature diderential is maintained between the air andthe castings; then removing the cooled castings from one end of the series at substantially the same rate as hot castings, as taken from the molds, are added to the other end of the series to maintain the temperature conditions and the length of the series substantially constant during working conditions.

20. The method of treating large castings, such as lngot molds and the like, which method comprises arranging the castings in a heat-graded series of a predetermined length; subjecting the castings to cooling air, and maintaining the heat gradient of the air slightly lower than the heat gradient of the series of castings whereby a suitable temperature difl'erential is maintained between the air and the castings; then removing cooled castings from one end ot the series at substantially the same rate as hot castings, as taken from the molds, are added to the other end of the series to maintain the temperature conditions and the length or the series substantially constant during working conditions.

21. The method of treating large castings, such as ingot molds and the like, which method comprises removing the casting from the mold sand as soon as the casting may be handled with safety; maintaining the casting at substantially the temperature at which it is removed from the mold for a predetermined period of time; then subjecting the casting to a heated cooling fluid which is gradually cooled to maintain a heat diderential between the cooling fluid and the casting, which differential gradually decreases as the temperature of the casting lowers.

22. The method of treating large castings,-

such as ingot molds and the like, which method comprises removing the casting from the mold sand as soon as the casting till lid

lltlh lltl may be handled with safety; maintaining the casting at substantially the temperature at which it is removed from the mold for a predetermined period of time; then causing the casting to travel through a heated cooling fluid which is gradually cooled to maintain a heat differential between the cooling fluid and the casting, which differential gradually decreases as the temperature of the casting lowers.

The method of treating large castings, such as ingot molds and the like, which method comprises removing the casting from the mold sand as soon as the casting may be handled with safety; maintaining the casting at substantially the temperature at which it is removed from the mold for a predetermined period of time; then causing the casting to travel through a heated cooling fluid which is gradually cooled to maintain a heat differential between the cooling fluid and the casting, which differential g'adually decreases as the temperature of the casting lowers, controlling the rate of travel of the casting to control the differential of temperature.

24. The process of cooling large articles of hot metal to prevent the formation of unequal internal stresses in the article, which method comprises arranging the articles in a loose elongated group within a covered channel having walls formed of slow heat conducting materials; passing air through the grouped articles; removing articles from one end of the group and adjacent the entrance for the cooling air; and adding hot articles to the other end of the group whereby the length of the group is maintained substantially constant during working conditions.

2-5. The method of cooling large hot metal articles to prevent the formation of undesirable internal stresses therein, which method comprises removing a hot article from a fabricating device as soon as the article may be handled with safety; providing a confined cooling fluid having a decreasing temperature gradient which ranges between a temperature slightly below that of the hot article to substantially atmospheric temperature; subjecting the article to the cooling fluid and providing a relative movement between the article and the cooling' fiuid in such manner that the article is caused to gradually lose its temperature.

26. The method of cooling large articles fabricated by use of heat, to prevent the formation of undesirable internal stresses in the article, which method comprises ar-i ranging the hot articles in a longitudinally extended group within a covered channel; providing a cooling fluid within, the channel, with the cooling fluid having a decreasing temperature gradientwhich ranges from a temperature slightly less than the hot article to substantially atmospheric temperature; then causing each article in the group to be subjected to the full range of temperature of the cooling fluid.

27. A cooling device for large castings, such as ingot molds and the like, comprising in combination a chamber adapted to receive hot castings, a suitable floor within said chamber, a conduit for withdrawing air from said chamber, and means to control the withdrawal of the air, said chamber being constructed to provide for the removal of the cooled castings and the addition of hot castings, the means to control the air being operable'to cause the air current to proceed from the cool castings toward the hot castings.

28. A cooling device for large castings, such as ingot molds and the like, comprising in combination a continuous chamber ad apted to receive hot castings, a suitable floor within said chamber, and means to control the withdrawal of the air, said chamber being constructed to provide for the removal of the cooled castings and the addition of hot castings, the means to control the air being operable to cause the air current to proceed from the cool castings toward the hot castings.

29. A cooling device for large castings, such as ingot molds and the like, comprising in combination a chamber adapted to receive hot castings, a suitable floor within said chamber, a conduit for withdrawing air from said chamber, means to control the withdrawal of the air, said chamber being constructed to provide for the removal of the cooled castings and the addition of hot castings, the means to control the air being operable to cause the air current to proceed from the cool castings toward the hot castings, and means to cause a relative movement between the point where the air is with drawn and the individual castings.

30. A cooling device for large castings, such as ingot molds and the like, comprising in combination a continuous chamber adapt ed to receive hot castings, a suitable floor within said chamber, a conduit for withdrawing air from said chamber, means to control the withdrawal of the air, said chamher being constructed to provide for the removal of the cooled castings and the addition of hot castings, the means to control the air being operable to cause the air current to proceed from the cool castings toward 'the hot castings, and means to cause a relative movement between the point where the air is withdrawn and the individual castings.

31. A device for gradually cooling castings and the like, said device comprising in combination a covered chamber, means to withdraw air from said chamber toccause a current of air to circulate through a porlltll tllti lid till

llli Stlr tion of said chamber and means tor regulat ing. the air current, a door within said chamber and adapted to support castings to be cooled, said means for regulating the being adapted to control the movement u air through the said chamber in such manner that the cool air is dra'wninto said E hamber and heated air is withdrawn trom said chamber.

32. A device for gradually cooling castings and the lilre, said device comprising in combination a covered chamber, means to withdraw air from said chamber to cause a current of air to circulate through a portion of said chamber, and means for regulating the, air current, a movable floor within said chamber and adapted to support castings to be cooled, said means for regulating the air being adapted to control the move ment of air through the said'cham'ber in such manner that the cool air is drawn into said chamber and heated air is withdrawn from said chamber. v

33. A device tor gradually cooling castings and the like, said device comprislng 1n combination a covered chamber, means to withdraw air from said chamber to cause a current of air to circulate through a portion of said chamber, and means for regulating the air current, a movable floor withinsaid chamber and adapted to support castings to be cooled, means to move said door, said means for controlling the air being adapted to control'the movement of am through the said chamber in such manner that the cool air is drawn into said chamber and heated air is withdrawn from said chamber.

34b. A device for gradually cooling cast-- ings and the like, said device comprising in combination a covered chamber, means to withdrav air from said chamber to cause a current of air to circulate through a portion of said chamber, and means for regulating the air current, a movable lloorwithin said chamber and adapted to support castings to be cooled, said means for regulating the air being adapted to control the movement of air through the said chamber in a direction opposite to the movement of the floor.

35. A cooling device for large castings, such as ingot molds and the like, comprising in combination a circular chamber adapted to receive hot castings, a circular moving tloor within said chamber, a conduit for withdrawing air from said chamber, means to control the withdrawal of the air, said chamber being constructed to provide for the removal of the cooled castings and the addition of hot castings, the control means for the air being controlled to cause the air current to proceed from the cool castings toward the hot castings.

36. A cooling device for large castings, such as ingot molds and the like, comprising name in combination a chamber adapted to receive hot castings, a door within said chamber, a conduit for withdrawing air from said chamber, a plurality of means to control the withdrawal of the air, said chamber being constructed to provide for the removal o'lt' the cooled castings and the additionot hot castings, the control means for the air being controlled to cause the air current to proceed from the cool castings toward the hot cast ings, and also being adapted to control the distance the air travels over the castings.

37. A cooling device for large castings,

such as ingot molds and the like, comprising in combination a chamber adapted to receive hot castings, a door within said chamber, a conduit for withdrawing air from said chamber, means to control the withdrawal of the air, said chamber being constructed with a station to provide for the removal of the cooled castings and a separate station for the addition of hot castings, the control means for the air being controlled to cause the air current to proceed from the cool castings toward the hot castings.

38. A cooling device for large castings, such as ingot molds and the like, comprising in combination a circular chamber adapted toreceive hot castings, a circular moving floor within said chamber, a conduit for withdrawing air from said chamber, a plurality of means to control the withdrawal 0f the air, said chamber being constructed with a station to provide for the removal of the cooled castings and a separate station for the addition of hot castings, the control means for the air being controlled to cause the air current to proceed from the cool castings toward the hot castings, and also being adapted to control the distance the air travels over the castings.

39. A device for gradually cooling castings and the like, said device comprising a covered chamber, means to withdraw air from said chamber to cause a current of air to circulate through a portion of said chamber, means for controlling the air current, a floor within said chamber and adapted to support castings to be cooled, a charging station for hot castings, and a discharging station for cool castings, said air controlling means adapted to control the movement of air through the said chamber in such manner that the cool air is drawn into said chamber and heated air is \vithd awn from said chamber. y

40. A device for gradually cooling castings and the like, said device comprising a circular covered chamber, means to withdraw air from said chamber to cause a current of air to circulate through a portion of said chamber, means for controlling the air current, a movable floor within said cliamher and adapted to support castings to be cooled, a charging station for hot castings,

till! ttli Mill

and a discharging station for cool castings, said air controlling means adapted to control the movement of air through the said chamber in such manner that the cool air is drawn into said chamber at the discharging station and heated air is withdrawn from said chamber at a zone adjacent the charging station.

41 A device for cooling articles fabricated fromhot metal, said device comprising a covered chamber, means for Withdrawing air from said chamber to cause a circulation of air through said chamber, said chamber being adapted to contain a plurality of articles to be treated, and means to regulate the movement of air through said chamber to regulate the rate of cooling of the castings therein.

42. A device for cooling articles fabricated from hot metal, said device comprising a covered chamber, means for Withdrawing air from said chamber to cause a circulation of air through said chamber, said chamber being adapted to contain a plurality of articles to be treated, a charging station, a discharging station, and a hot zone adjacent the charging station.

48. A device for cooling articles fabricated from hot metal, said device comprising a covered chamber, means for Withdrawing air from said chamber to cause a circulation of air through said chamber, said-chamber being adapted to contain a-plurality of articles to be treated, and means to regulate the temperature differential between the castings and the cooling air.

44. A device for cooling articles fabricated from hot metal, said device comprising a covered chamber, means for Withdrawing air from said chamber to cause .a circulation of air through said chamber, said chamber being adapted to contain a plurality of articles to be treated, and means to regulate the time period each casting is subjected to the cooling am 45. A device for cooling articles fabricated from hot metal, said device comprising a covered chamber, means for withdrawing air from said chamber to cause a circulation of air through said chamber, said chamber being adapted to contain a plurality of articles to be treated, a charging station, a discharging station, means to regulate the time period each casting is subjected to the cooling air, a hot zone adjacent the charging station, and means to determine the period the castings are in the hot zone.

46. A device for cooling articles fabricated from hot metal, said device comprising a covered chamber, means for withdrawing air from said chamber to cause a circulation of air through said chamber, said chamber being adapted to contain a plurality of articles to be treated, means to regulate the temperature differential between the castings and the cooling air, and means to regulate the time period each casting is subjected to the cooling air.

47. A device for cooling articles fabricated from hot metal, said device comprising a covered chamber, means to cause a circulation of air through said chamber, said chamber being adapted to contain a plurality otarticles to be treated, a charging station. a discharging station, a. hot zone adj accnt the ehargingstation, and means to determine the period the castings are in the hot zone.

RAY Gr. COATES. 

